Intravenous administration sets have heretofore been provided. At least certain of these administration sets have had the drawback in that it is possible for air to be introduced into the same accidentally during use of the same. In addition to the dangers of introducing air into the administration set which could possibly be introduced into the patient with undesirable results, there is also the additional disadvantage in that the presence of air in the administration set may affect the accuracy of the pumping operation. The presence of air may also adversely affect alarm systems utilized in connection with such administration sets to give an alarm when the source of the intravenous liquid being administered is depleted. There is therefore a need for a new and improved intravenous administration set which overcomes the above named disadvantages.